Apparatus coating sheeted material with a tacky substance

ABSTRACT

An apparatus for treating a continuous web of material which has been coated with a tacky substance having means for moving the web along a first path having an upward vertical component to permit the substance to dry at least partially and to lose at least a portion of its tackiness. Means are provided for changing the direction of travel of the web to a second path having a downward vertical component and includes an absorbent surface positioned to contact the web and change the direction of travel. The absorbent surface is capable of absorbing a fluid which prevents the adherence of the partially set tacky substance to the absorbent surface.

United States Patent [191 Rizzo 1 Mar. 19, 1974 1 APPARATUS COATINGSHEETED [73] Assignee: Afco Products Inc., Somerville,

, Mass.

[22] Filed: Mar. 15, 1972 [21] Appl. No.: 234,776

Related US. Application Data [60] Division of Ser. No. 66,104, Aug. 21,1970, Pat. No. 3,681,121, Continuation of Ser. No. 580,656, Sept. 20,1966, abandoned.

[52] US. Cl 118/69, 118/70, 118/257, I 118/419, 198/203 [51] Int. Cl.B05c 11/12 [58] Field '01 Search 118/70, 69, 104, 419, 420, 118/106,257; 117/102 M, 119.2, 119.4; 34/3 1,759,600 5/1930 Wilshire 118/104 X2,218,249 10/1940 Nadeau et a1 118/70 2,532,985 12/1950 Bannon et al,...34/D1G. 3 2,843,505 7/1958 Riedel ll8/104X 2,892,263 6/1959 Hornbostel34/DIG. 3 3,175,532 3/1965 Mugg1eton.... 118/119 3,387,585 6/1968Farrell 118/104 3,524,425 Barnes et a1. 118/106 X Primary ExaminerMorrisKaplan 'Attorney, Agent, or F irm -Lane, Cutlien, ounfiei'a Ziems V [57]ABSTRACT An apparatus for treating a continuous web of material whichhas been coated with a tacky substance having means for moving the webalong a first path having an upward vertical component to permit thesubstance to dry at least partially and to lose at least a portion ofits tackiness. Means are provided for changing the direction of travelof the web to a second path having a downward vertical component andincludes an absorbent surface positioned to contact the web and changethe direction of travel. The absorbent surface is capable of absorbing afluid which prevents the adherence of the partially set tacky substanceto the absorbent surface.

5 Claims, 4 Drawing Figures PATENTEUHAR 191974 I 020/5 MAM/vs APPARATUSCOATING SHEETED MATERIAL WITH A TACKY SUBSTANCE This is a division ofU.S. Pat. application Ser. No. 66,104, filed Aug. 21, 1970, now U.S.Pat. No. 3,681,121, issued Aug. 1, 1972, which in turn is a continuationof U.S. Pat. application Ser. No. 580,656, filed Sept. 20, 1966, nowabandoned.

This invention relates to an apparatus for coating a continuous webmaterial with a tacky substance.

In the conventional process for making materials which are coated with asticky or tacky substance, such as flashing, waterproofing and roofingmaterials, a continuous web material is passed through a dip-tank of thecoating substance, which is preferably (but not limited to) an asphaltor bituminous compound. The

amount of coating on both ides of the web is controlled by the heat ofthe coating substance in conjunction with various mechanical means tosmooth the coating. After leaving the dip-tank the coating substance onthe web material is in a heated and sticky or tacky state. The web mustthen be cooled and the coating set so that it may be wound on a take-uproll without the layers sticking together.

' Oneconventional method to accomplish this cooling and setting is todrive the coated web vertically by means of a driven roll system at anupper position, preferably past cooling fans, over the driven rollsystem (at which point the web reverses direction) and to return thecoated web to the lower position where it is finally wound on a suitabletake-up roll after passing over a series of ground levelrolls. Thisvertical movement provides a maximum amount of space within which thecoating may be cooled with a minimum of floor space being used. Thevertical length of travel is limited, however, because the weight of thecoated web often causes tension problems, which in turn createtearingand web breaking since the web is supported at its upper position by theaforementioned driver roll system. This limits the amount of cooling ofthecoated web. lf the coating on the web is not sufficiently set andcooled, it will stick to the driven roll system at the top of thevertical run. If the coating is still hot and tacky when it reaches the.ground level rolls, sticking to these rolls will also occur. Finally, ifthe coated web is not completely cooled when it is wound on the take-uproll, the layers will stick to each other and will not be able to beunwound at their point of sale or use.

Various methods have been utilized to attempt to eliminate the tackycondition and to cool the coated web to overcome the aforementionedproblems. Conventional coating materials such as asphalt or bituminouscompositions have poor heating and cooling characteristics. Cooling ofthe heated coated web on both surfaces as it travels in the verticaldirection between the dip-tank and the driven and idler rollers at theupper position of travel helps reduce the sticking problem somewhat butthe sticking still occurs to an unsatisfactory degree. Refrigerationcooling has been attempted but is expensive and slows production to alevel where it is not economically possible to operate the process. Noappreciably favorable results have been obtained by refrigerating orsimilarly cooling the driven roll itself at its upper driving position.

It is at this-upper position at the superstructure where the greatestefforts and expense have been expended to eliminate the problem ofsticking, so that the web may be wound into a finished product.

For example, various water treatment methods have been attempted at thispoint in the process with little success. An open tank placed at theupper position at the end of the vertical run has been filled with waterwith a metal driven roll immersed in it. While this presents acontinuously wctted roll to the coated web, the metal surface of thedriven roll does not pick up and transfer sufficient water to the coatedweb to eliminate the sticking problem. Another water treatment methodattempted has involved the immersion of the coated web in water withinan open tank in order to effect coding and reduce the tacky state of thecoating. However, a water pick-up problem with the coated web resultswhich renders this method unsatisfactory. The driven roll and thesubsequent idler rolls have also been coated with a non-adherent plasticmaterial, such as Teflon, with no success in eliminating the stickingproblem.

The only method that has been commercially practicable and which iscurrently in use involvesthe application of a powder material such as;talc and/or mica to one or both sides of the coated web at the top ofthe vertical run at the upper superstructure position. However, thismethod has continuously presented problems both of housekeeping andapplication. In order for the tale powder to properly adhere to thecoated web, fine mesh talc powder must be used. Although variousattempts have been made to confine the application of the tale powder tothe coated web, housekeeping problems occur, particularly due to thedust formed Thus dust affects both the machinery and the health of theemployees and causes maintenance costs to be high. Attempts tocompletely enclose the upper superstructure position to make arelatively air-tight chamber were not effective since they resulted inthe jamming of the equipment within the chamber. In addition, the taledust escaped out of the slits through which the coated web was adaptedto pass. This greatly reduced the effectiveness of this method.

Further methods of applying the tale powder were attempted such asplacing the upper superstructure in a negative exhaust pressure chamberand applying the talc in a slurry state. Both ofthese additional methodshave had similar shortcomings.

In addition to the foregoing, the use of materials such as talc presentssecondary problems related to control of the amount of talc used. Whentoo little of the talc powder is used, the layers of the coated webstick together and problems in unrolling the material from the take-uproll result. When too much of the tale powder is used, problems occur inthe saleability of the product, since the excess powder decreases itsattractiveness and presents handling problems.

In addition to those listed above, other attempts to eliminate theforegoing problems have been made by applying various release papersand/or plastic films on both sides of the coated web, such as wax-kraftpaper, chemically treated paper, polyethylene films, mylar films,cellophane films, polyvinylchloride 'films and so forth. Some of thesefilms have reduced the problems of sticking and facilitated the talepowder application but they have created other difficulties since therelease papers or films must be removed from the finished product beforeit is wound on the wind-up roll.

This use of release papers or films is accordingly undesirable since itincreases manufacturing costs.

Still further attempts have been made to eliminate the problems involvedin the process by spraying the coated web with water on one or bothsides during the vertical travel distance between the dip-tank and theupper superstructural position. However, this created a water collectionproblem since the water tended to run off down the coated web into thedip-tank.

The present invention provides an apparatus for continuously coating anelongated sheet of material with a tacky substance wherein theabove-mentioned disadvantages are eliminated. This invention broadlyinvolves the cooling and drying of the tacky substance by causing thecoated sheet of material to pass over and in contact with an absorbentsurface which contains an absorbed fluid which will prevent the coatedsheet of material from sticking to the absorbent surface and which, in apreferred embodiment, will cool the tacky substance as it comes incontact with the absorbent surface.

It is accordingly a primary object of the present invention to provide anovel coating apparatus wherein a continuous web coated with a tackysubstance is treated to prevent sticking.

It is a further object of the present invention to provide a novelcoating apparatus wherein a continuous web coated with a tacky substanceis wetted and cooled through contact with a liquid contained in anabsorbent surface to eliminate sticking problems.

It is still another important object of the present invention to provideapparatus including a novel absorbent surface which makes possible thewetting and cooling of a tacky coated web to prevent sticking.

These and further objects and advantages of the present invention willbecome more apparent through reference to the following description andappended claims, as well as to the accompanying drawings wherein:

FIG. 1 is a diagrammatic representation of the coating process of thepresent invention;

FIG. 2 is an isometric view of the wetting and cooling endless beltapparatus of the invention;

FIG. 3 is a view of an alternate apparatus of the invention; and

FIG. 4 is aview of another alternate apparatus of the invention.

The novel apparatus and method of the present invention may best bedescribed by reference to FIGS. 1 and 2 of the drawings. While thepresent process is applicable to the coating of any elongated sheet ofmaterial with a sticky or tacky substance, whether such substance is ahot melt material or one which is a cool fluid, the invention will bedescribed in connection with a preferred embodiment involving anelongated web or sheet of material coated with a hot-melt asphalticsubstance.

An elongated sheet of material to be coated passes from a supply roll 12over an idler roll 14 into a dip tank 16 which contains asphalt 17 whichis heated to a sufficiently fluid condition by conventional heatingmeans (not shown). Since sheet 10 passes into tank 16 around idler rolls18 and 20, the sheet will be coated on both sides with the asphalt 17.The amount of coating on the web material 10 is controlled by heat inconjunction with spreader blades (not shown) which are mounted bothabove the dip-tank 16 and above the level of the asphalt compositionwithin the tank 16 above the idler rolls l8 and 20.

As the asphalt coated web 10 leaves the heated diptank 16, thetemperature of the coating is approximately 275 F. The coated web 10travels vertically a distance of approximately 15-20 feed where itpasses over an endless belt 24 which is carried by a driven roll 22 andidler roll 26. The structure including the novel endless belt 24 will bedescribed hereinbelow in greater detail. The coated web 10 then proceedsdownward to ground level to driven rolls 28 and 30, over idler roll 32and finally is wound on a'take-up roll 34.

In roofing materials, waterproofing, flashings and building productapplications, consumers expect their products to be provided withdecorative materials such as coarse mica flakes, roofing granules, sandand/or other materials. Where the coated sheets made in accordance withthe present invention are destined for such applications, the decorativeor like materials are applied to the coated sheet 10 by applicatormechanism 42 which is positioned immediately above driven rolls 28 and'30. When the coated web 10 reaches its lower position at the drivenrolls 28 and 30, it is still slightly tacky. This permits the decorativematerials to adhere to the surface of the coated web 10. The rate offlowof these materials from applicator mechanism 42 can be controlled byany conventional mechanical or electrical means. Excess decorativematerials, which might fall off the coated web 10, can be collected inan open pan 44 which is positioned under the point of application andthe collected material may be reused.

As indicated above, details of the novel endless belt structure of thepresent invention are shown in FIG. 2. An endless belt 24, which ispreferably made of a solid woven cotton material which is adapted toabsorb and hold water, is mounted on driven roll 22 and idler roll 26.The endless belt 24 is mounted over a tank 36 which is filled with acooling fluid such as water so that the lower portion of the belt passesthrough the water and becomes wetted.

Water is introduced into tank 36 by means of a perforated pipe 38 whichsprays water on the inner surface of the endless belt 24, as shown, withthe excess water not adhering to the underside of the belt 24fallinginto the tank 36. Spraying is regulated by a valve (not shown)which controls the flow of water. The level of water within the tank 36is regulated by an overflow drain 40 which is positioned near the top ofthe tank. Endless belt 24 is driven through the tank 36 by the drivenroll 22 and as it revolves it picks up water. At the end of the verticalrun from the dip-tank 16, the hot and tacky asphalt coated web 10 passesover the wetted endless belt 24. As will be apparent from FIGS. 1 and 2,revolution of the driven roll serves not only to drive the endless belt24 but to move coated sheet 10 through the coating system.

The endless belt 24 around driven roll 22 and idler roll 26 may beadjusted for tension by adjustable bearings on the arbors of the idlerroll 26. Tracking can be controlled by crowning or movement of idlerroll 26.

amount of water is picked up by the endless belt 24 and brought incontact with the coated sheet to cool and set the coating so as toeliminate sticking problems without the attendant water pick-up problemswhich occur when the coated sheet 10 is completely immersed in water ashas been done in prior art processes. After the coated sheet 10 passesover the endless belt 24 at the idler roll 26, it is still sufficientlywarm to dissipate the small amount of water film which was picked upfrom the. endless belt 24 and remains on the surface of the coated sheet10. Further drying of this water, if necessary, can be accomplished bysuitable radiant heat bulbs or other warm air circulation anywhere inthe process during its downward travel. Since the coated web 10 does notstick to the endless belt 24, the problem of the coating sticking on thedriven and idler rolls (as in prior art methods) is completelyeliminated. As will be appreciated, the vertical distance which theasphalt coated sheet 10 travels from the dip-tank 16 to the driven roll22 aids in cooling and setting of the asphalt coating. When the novelapparatus in the present coating process is used, the vertical distancefrom the dip-tank to the driven roll 22 may be reduced substantiallywithout adverse effect, thus permitting a saving in the building height.

As will also be recognized, by increasing the length of endless belt 24,the coated sheet would be in contact with the wetted surface for alonger period and the cooling and setting effect on the coating would beenhanced correspondingly. Conversely, by decreasing the length of theendless belt, the coated web will not be I cooled as much. The endlessbelt length can be varied to provide the exact degree of cooling desiredin a particular application. a i

As previously indicated, the cooling fluid (water, in the preferredembodiment) is fed into tank 36 by means of a perforated pipe 38. Sincethis pipe is arranged to spray water on the inner surface of the endlessbelt 24, this feed arrangement serves the dual purpose of feedingcooling fluid into tank 36 and enhancing thecooling effect on theendless belt.(and thus ultimately on the tacky coating on sheet 10).While this is accordingly a highly advantageousarrangement, the basicadvantages of the novel system of the presentinve ntion can still beattained with a conventional cooling fluid feed arrangement in tank 36.

Various modifications of the foregoing system are possible and practicalwithin the spirit of the present invention. For example, as shown inFIG. 3, the endless belt-driven roll-idler roll combination can becompletely eliminated by wrapping a length of material 50 similar to thewoven cotton belt of the above-described apparatus completely around theperipheral face of a driven roll 52 so that the periphery of this rollis completely covered. This roll is then partly submerged in a watertank 54 (as driven roll 22 was in tank 36) so that material 50 absorbswater as it rotates. By elimination of the idler roll (which is notnecessary in the system of FIG. 3), the coated web travels directly tothe lower position at which final decorative additions are made i andfinal winding of the coated sheet takes place. This construction wouldbe practical'where the sticking and cooling problems are not as great asthose described above.

Another variation of the single roll wetting apparatus shown in FIG. 4,eliminates the need of passing the roll through a water tank. In thisembodiment, the driven roll is hollow and has a porous peripheral face62. A water inlet 64 and water outlet 66 are provided in the ends of theroll 60 with roll 60 being mounted in appropriate rotary jointspermitting pressurized water ingress and egress as roll 60 rotates.Water or other cooling fluid applied to the interior of the driven roll60 under pressure is forced through the porous face 62 of the roll 60and wets the coated web passing over it to wet it, as in the previousembodiments discussed above. The volume and pressure of the water iscontrollable and variable so more or less water can be presented to thecoated web. A drip pan 68 is provided to collect excess water whichfalls from the porous face 62 of the driven roll 60.

The preferred material for use in fabricating the endless belt 24 (orthe corresponding absorbant surface used in the embodiments of FIGS. 3and 4) is a cotton belting, an excellent form of such belting being a2-ply Easton white solid woven cotton belting (endless net length squarelap). 'Other absorbent materials can be employed, however, to obtain thebenefits of thepresent invention.

Similary, while the present invention is particularly adapted fortreating tacky coatings such as asphaltic or bituminous substances,the'novel process and apparatus previously described are adapted for usefor a variety ofpurposes, including the manufacture or processing ofbutyl products, neoprene, polyvinyl chloride, reinforced ornon-reinforced sheets or films and the like, wherever cooling andsticking problems of the nature previously described are encountered.And while the present invention has been described in connection withhot melt materials, tacky coating substances which are not heated may besimilarly employed, in which case any heating means provided in tank 16will be unnecessary.

A variety of web orsheet materials can be coated in the process andapparatus of the present invention. Exemplary of such materials aremetal foils, rag and asbestos felts, paper and. plastic films, non-wovenans woven cotton cloths, wire meshes, fiberglass cloths, burlap clothsand the like.

In addition to advantages previously discussed, with the novel coatingprocess and apparatus of the present invention, the necessity forapplying talc powder to the web is eliminated. This reduces costs anddoes away with the unhealthy environment and the housekeeping problemscaused by talc dust. The process of the present invention also improvesthe appearance of the product and facilitates laminating or bonding ofother webs onto the coated webs.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment and processes are therefore to be considered in all aspectsas illustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and. range ofequivalency of the claims are therefore intended to be embraced therein.

I claim:

l. Apparatus for treating a continuous web of material which has beencoated with a tacky substance characterized as generally adhering toboth relatively warm and relatively cool surfaces while tacky,comprising: means for applying said tacky substance to said web ofmaterial; means for moving said coated web of material along a firstpath having an upward vertical component to permit said substance to dryat least partially and to lose at least a portion of its tackiness;means for changing the direction of travel of said web from said firstpath to a second path having a downward vertical component, saidchanging means including an absorbent surface intermediate said firstand said second path positioned to contact said web of material andchange the direction of travel of said web as said web is moved alongsaid paths after said substance has dried at least partially and lost atleast a portion of its tackiness,,said absorbent surface being capableof absorbing a fluid which prevents the adherence of said partially settacky substance to said absorbent surface, and means for supplying saidfluid to said absorbent surface which will prevent said coated sheet ofmaterial from sticking to said absorbent surface, said fluid supplyingmeans comprising an endless loop which defines said absorbent surfaceand which is fabricated of a material capable of absorbing said fluidand transferring said fluid to said absorbent surface, means forcontaining a body of fluid to be absorbed within which at least aportion of said absorbent surface is immersed, and auxiliary fluidsupply means for providing a second source of sprayed fluid to saidabsorbent surface and for replenishing the fluid in said body of fluid.

2. Apparatus as defined in claim 1 further including means for drivingsaid endless loop in contact with said sheet of material so as to movesaid sheet of material along said paths.

3. Apparatus as defined in claim 1 wherein means are provided to spraysaid fluid to be absorbed on the radially inward surface of said endlessbelt.

4. Apparatus as defined in claim 1 wherein said auxiliary fluid supplymeans include means to spray said fluid to be absorbed on the radiallyinward surface of said endless belt.

5. Apparatus as defined in claim 1 additionally including means forspraying said fluid to be absorbed on the radially inward surface ofsaid endless belt, said containing means being positioned relative tosaid endless belt so that fluid to be absorbed which drains off saidendless belt will fall into said containing means.

1. Apparatus for treating a continuous web of material which has beencoated with a tacky substance characterized as generally adhering toboth relatively warm and relatively cool surfaces while tacky,comprising: means for applying said tacky substance to said web ofmaterial; means for moving said coated web of material along a firstpath having an upward vertical component to permit said substance to dryat least partially and to lose at least a portion of its tackiness;means for changing the direction of travel of said web from said firstpath to a second path having a downward vertical component, saidchanging means including an absorbent surface intermediate said firstand said second path positioned to contact said web of material andchange the direction of travel of said web as said web is moved alongsaid paths after said substance has dried at least partially and lost atleast a portion of its tackiness, said absorbent surface being capableof absorbing a fluid which prevents the adherence of said partially settacky substance to said absorbent surface, and means for supplying saidfluid to said absorbent surface which will prevent said coated sheet ofmaterial from sticking to said absorbent surface, said fluid supplyingmeans comprising an endless loop which defines said absorbent surfaceand which is fabricated of a material capable of absorbing said fluidand transferring said fluid to said absorbent surface, means forcontaining a body of fluid to be absorbed within which at least aportion of said absorbent surface is immersed, and auxiliary fluidsupply means for providing a second source of sprayed fluid to saidabsorbent surface and for replenishing the fluid in said body of fluid.2. Apparatus as defined in claim 1 further including means for drivingsaid endless loop in contact with said sheet of material so as to movesaid sheet of material along said paths.
 3. Apparatus as defined inclaim 1 wherein means are provided to spray said fluid to be absorbed onthe radially inward surface of said endless belt.
 4. Apparatus asdefined in claim 1 wherein said auxiliary fluid supply means includemeans to spray said fluid to be absorbed on the radially inward surfaceof said endless belt.
 5. Apparatus as defined in claim 1 additionallyincluding means for spraying said fluid to be absorbed on the radiallyinward surface of said endless belt, said containing means beingpositioned relative to said endless belt so that fluid to be absorbedwhich drains off said endless belt will fall into said containing means.